Self-threading needles

ABSTRACT

A sewing machine needle with the pointed extremity formed with a slot extending upwardly into the bottom of the needle eye to define a minor point at one side of and above the main needle point. The slot is nonplanar in transverse configuration and provides a concave recess into the side of the main needle point into which recess the minor point is bent.

United States Patent inventor Appl. No.

Filed Patented Assignee Stanley J. Ketterer Morris Plains, NJ. 34,162

May 4, 1970 June 1, 1971 The Singer Company New York. Y.

SELF-THREADING NEEDLES 4 Claims, 6 Drawing Figs.

US. Cl

Field of Search [5 6] References Cited UNITED STATES PATENTS 286,01410/1883 Jenkins Primary Examiner-Richard J. Scanlan, Jr.

Attorneys-Marshall J. Breen, Chester A. Williams, Jr. and

Robert E. Smith ABSTRACT: A sewing machine needle with the pointedextremity formed with a slot extending upwardly into the bottom of theneedle eye to define a minor point atone side of and above the mainneedle point. The slot is nonplanar in transverse configuration andprovides a concave recess into the side of the main needle point intowhich recess the minor point is bent.

' PATENTE-D Jun nan INVIiN'IOR. Stanley J. Kefrerer AYTORNE Y WITNESSSELF-THREADING NEEDLES BACKGROUND OF THE INVENTION In order to thread anordinary eye-pointed sewing machine needle, an end of a thread must bepassed through the needle eye. To avoid this tedious threadingprocedure, many selfthreading needle constructions have heretofore beenproposed in which a slot is provided leading to the needle eye andthrough which the thread may be introduced laterally into the needleeye. These prior self-threading needles have not been entirelysatisfactory because each has failed to satisfy one or more of thefollowing criteria for a successful selfthreading needle:

1. It must prevent escape of the thread from the needle eye duringsewing.

2. It must not pick (admit undesired strands of thread or work to theneedle eye).

3. It must not materially weaken the needle.

4. It must be economically competitive.

The US. Pat. No. 112, 980, Mar. 21, 1971, is typical of a constructionin which the needle is slotted alongside the eye. This construction hasthe principal disadvantage that is provides a multiplicity of pointswhich are susceptible to picking work fibers not only during needlepenetration of the work, but also during withdrawal.

The US. Pat. No. 100, 112, Feb. 22, 1870, has the disadvantage that it18 slotted both below and above the needle eye. In sewing on the needledownstroke, both limbs of thread in the needle eye are drawn tightlyagainst the top of the needle eye, and any slot extending from the topof the needle eye, therefore, invites disadvantageous escape of thethread from the eye. This patented needle is also susceptible to thedisadvantage of picking work fibers. It is pointed out that when aneedle penetrates a workpiece, it stretches and forces aside the fiberswhich, therefore, are urged back against the needle. By simply locatinga point on the needle within the axial projection of the needle shankelsewhere along its length, by no means avoids the possibility ofpicking because the work fabric fibers tend quickly to assume thecross-sectional shape of the needle and this is particularly so where aslabbed or planar cut is made in the side of a needle.

The US. Pat. No. 493, 399, Mar. 14, 1893, discloses a typicalconstruction which avoids the possibility of picking by extendingthethreading slot upwardly beyond the extent to which the needlepenetrates the work fabrics. The expense of forming the long slot, thedegree to which the needle blade is weakened, and the propensity forescape of thread from the needle eye make such needles unsuccessful.

BRIEF SUMMARY OF THIS INVENTION In this invention a self-threadingsewing machine needle is provided by including on a conventional needle,a slot either arcuate, V-shaped or otherwise nonplanar in transverseconfiguration, which extends from near the needle point upwardly to thebottom of the needle eye. The minor point on the side of the needleformed by the slot is then bent into the concave recess formed by thenonplanar slot.

Since during sewing, both limbs of a thread in the needle eye are neverdrawn against the bottom of the needle eye, escape of a thread once inthe eye is obviated.

The single minor point on the needle cannot pick because it is locatedwithin a concave recess into which the stretched work fabric fibers willnot enter.

The strength of even the smallest diameter needles will not bematerially weakened by the construction of this invention since the slotis parallel with the principal direction in which load is applied to theneedle.

The very short and the absence of complicated or critical assembly orfinishing operation make this needle economically attractive.

With the above and additional objects and advantages in view as willhereinafter appear this invention is illustrated in the accompanyingdrawing of a preferred embodiment in which:

FIG. 1 is an elevational view of the tip of a sewing machine needletaken from a direction exposing the needle eye and showing the threadingslot as it is formed in the needle,

FIG. 2 is an elevational view of the tip of the sewing machine needle asin FIG. 1 but illustrating the minor point formed by the slot after ithas been polished and bent,

FIG. 3 is a right side elevational view of the tip of the sewing machineneedle of FIG. 2,

FIG. 4 is an elevational view of a sewing machine needle made asillustrated in FIG. 2 and shown secured in a sewing machine needle clampwith a thread loop in place on the needle point and drawn to one side inpreparation for insertion of the thread into the needle eye,

FIG. 5 is a cross-sectional view of the needle taken substantially alongline 5-5 of FIG. 2, and' FIG. 6 is a cross-sectional view of the needletaken substantially along line 6-6 of FIG. 2.

DETAILED DESCRIPTION Illustrated in the accompanying drawing is a sewingmachine needle 11, which apart from the self-threading constructionbelow the thread accommodating eye 12, is conventional.

The needle 11 includes an enlarged butt 13 adapted to be received in aneedle clamp 14 carried on a sewing machine needle bar (not shown).Extending from the butt is a needle blade 15 preferably of cylindricalform and provided on diametrically opposite sides with lengthwisegrooves 16 and 17. One of the grooves 16, referred to as the long grooveextends from the needle butt 13 to the tapered point 18 of the needlebelow the needle eye 12, while the other groove 17 which is referred toas the short groove is formed only in the vicinity of the needle eye.The grooves 16 and 17 accommodate the needle thread during workpenetration by the needle in sewing and influence, for instance, theformation of loops in the proper limb of the needle thread for desiredcooperation with the sewing machine loop taker.

The sewing machine needle, which as thus far described can be threadedby passing an extremity of a sewing thread endwise through the needleeye, is made self-threading in accordance with this invention by theprovision in the tapered point 18 of a thread entry slot 20 extendingfrom slightly above the tip 21 of the tapered point 18 to the bottom ofthe needle eye 12.

As shown in the cross-sectional views FIGS. 5 and 6, the thread entryslot is nonplanar in transverse configuration and may, for instance, becircular in form. The slot 20 may be cut by a tubular cutter havingsubstantially the same outer diameter D as the needle shank 15. Aportion of such a cutter is shown at 25 in FIG. 6. This cut may beformed readily by the known techniques of electrodeposition milling. Itwill be appreciated that the transverse configuration of the slot is notlimited to a circular shape but might also be formed in a V- shape orthe like which would result in formation of a concave recess 26 in thetapered needle point 18 as best shown in FIG. 6. The lips 27 and 28, oneat each side of the concave recess in the needle point 18 provideprotective shields across which the fibers of a work fabric can stretchas along line X-X of FIG. 6 during needle penetration so that the recess26 defines a pocket in which the work fabric fibers do not enter.

Formation of the thread entry slot 20 defines alongside the main needlepoint 18, a minor point 30 which terminates above the main needle point18 and as shown in FIG. 1 proud of the recess 26 immediately after theslot 20 is cut. As a final step, in the manufacture of theself-threading needle of this invention, the minor point 30 which isshortened somewhat by polishing and deburring, is bent inwardly towardthe main needle point 18 until the minor point 30 is disposed within therecess 26 as shown clearly in FIGS. 2 and 6. In this way, the minorpoint is shielded against picking strands of work fabric during needlepenetration.

H0. 4 illustrates the manner in which a thread T may be insertedlaterally into the needle eye 20. A loop of the thread is placed aroundthe needle shank and drawn down onto the main needle point 18 below theminor point 30. The thread loop is then drawn sideways to the left asviewed in FIG. 4 to flex the main needle point away from the minor point30 and open the thread entry slot 20. While maintaining the sidewayspull to keep the minor point 30 out of the recess 26 as shown in FIG. 4,the thread T is drawn upwardly into the slot 20 and into the needle eye12. When the lateral force of the thread is removed, the main needlepoint 18 will return to the position shown in FIG. 2 and the thread willbe confined in the needle eye.

Having thus set forth the nature of this invention, what I claim hereinis:

l. A self-threading sewing machine needle including a blade fonnedtransversely with a thread accommodating eye and with a taperedextremity beneath said threaded accommodating eye defining a main-needlepoint, said needle being fonned with a thread entry slot extending fromone side of said main needle point and leading upwardly into the bottomof said thread accommodating eye, said slot being nonplanar intransverse configuration providing a concave recess into the side of themain needle point and defining a minor point at one side of said needle,said minor point being bent inwardly toward said tapered extremity andinto a position completely within said concave recess.

2. A self-threading needle as set forth in claim 1 in which said needleblade is formed with diametrically opposed lengthwise grooves betweenwhich grooves said thread accommodating eye extends, said thread entryslot extending upwardly along said grooves and into the bottom of saidthread accommodating eye.

3. A self-threading needle as set forth in claim 1 in which said threadentry slot extends at an angle of no greater than 3 relatively to thecentral axis of the needle blade.

4. A self-threading needle as set forth in claim I in which the threadentry slot is circular in transverse configuration and has an outsidediameter substantially equal to that of the needle blade.

$373 3? WIINITED STATES PQTENT OFFICE CERTIFICATE OF CORRECTION DatedJune 1, 1971 Patent No. 3, 581, 688

Inventor(s) Stanley J. Ketterer It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

"1971 should read 1871 Column 1, line 22,

Column 4, line 14, insert degrees after "3".

Signed and sealed this 31st day of August 1971 (SEAL) Attest:

EDWARD M.FLETCHEH, JR. WILLIAM E. SCHUYLER, JR, Attesting OfficerCommissioner of Patents

1. A self-threading sewing machine needle including a blade formedtransversely with a thread accommodating eye and with a taperedextremity beneath said threaded accommodating eye defining a main needlepoint, said needle being formed with a thread entry slot extending fromone side of said main needle point and leading upwardly into the bottomof said thread accommodating eye, said slot being nonplanar intransverse configuration providing a concave recess into the side of themain needle point and defining a minor point at one side of said needle,said minor point being bent inwardly toward said tapered extremity andinto a position completely within said concave recess.
 2. Aself-threading needle as set forth in claim 1 in which said needle bladeis formed with diametrically opposed lengthwise grooves between whichgrooves said thread accommodating eye extends, said thread entry slotextending upwardly along said grooves and into the bottom of said threadaccommodating eye.
 3. A self-threading needle as set forth in claim 1 inwhich said thread entry slot extends at an angle of no greater than 3relatively to the central axis of the needle blade.
 4. A self-threadingneedle as set forth in claim 1 in which the thread entry slot iscircular in transverse configuration and has an outside diametersubstantially equal to that of the needle blade.